Absorption refrigeration system



Aug. 1s, 1936.

P. KHLER 2,051,723

ABSORPTION REFRIGERATION SYSTEM Original Filed Nov. ll, 1930 IN VEN TOR.

Pefer Khler %&%aw% ATTORNEY.

Patented Aug. 18, 1936 UNITED STATES PATENT OFFICE Peter Khler, Stockholm, Sweden; assignor, by mesne assignments, I;o Servel, Inc. Dover, Del., a corporation of Delaware Original application November 11, 1930, Serial Divided am! this application March 25, 1933, Serial N0. 662,653. Rem'zwed July 31, 1934. In Germany January 24, 1930 15 Claims.

This invention relates to absorption refrigerating systems of the pressure equalized type anti more particularly to the circulation of flu.ids in such systems. The present invention is a division of my application Serial N0. 494,827, filed November 11, 1930.

Among the objects cf the invention are 1:0 provide improved liquid circulation and distribution in the system. reduction in the amount of energymequired to produce circulation, improved contact between gas and solution in the absorber, and increased cooling of the absorber, with resulting improved efliciency of the system.

Other objects and advantages cf 'this invention will be apparent from the fbllowing description taken in Connection with the accompanying drawing, in which,

Fig. 1 shows schemati'cally a. refrigerating system embodying the invention; und

Fig. 2 is a cross section of the absorber shown in Fig. 1.

Referring to the drawing, a. generator I containing a, solution of a. refrigerant in an absorption liquid such a.s ammonia in water is heated by a gasburner II. Ammonia. vap0r expelled from solution in the generator I0 flows in couduii; I2 through the rectifier I3 to the condenser II." In the rectifier I3 water vapor condenses out of the ammonia. anal drains back to the heiler through conduit I2. In the condenser I I the ammonia. vapor is condensed to liquid, which latter flows in conduit I5 to the evaporator I8 where it flows downwardly over baflie plates I1 evaporeing by diffusion into an inert pressure equalizing gas such as hydrogen which enters the evaporator through conduit I8.

The resu1ting gas mixture flows from the lower part of the evaporator I6 through conduit I9 to an absorber 20. In the latter the gas mixture comes in contact with weak absorption liquid which flows from the generator I0 to the absorber through conduit 2I es hereinafter described. Ammonia. is absorbed out of the gas mixture into the weak solution and the hydrogen or weak gas Teturns to the eva.porator through conduit I8. The warm weak gas fiowing through conduit I8 is brought into heat exchange relation with the cool rieb gas flowing through conduit I9 in the gas heat exchanger 22. Circulation o1 the gas between the absorb er and evaporator occurs due to the diiference in weights of the columns of rich und weak gas.

Enriched absorption liquid from the absorber 20 is conducted back to the generator I0 through conduit 23. Conduits 2I and 23 extend in heat exch ange relation ab 24 for transfer o! heat from the hat weak solution I:o the cool enriched absorption solution. Conduits 2I and 23 are counected to the heiler I0 on opposite sides thereof and a ba flie plate or partition 25 isprovided. as shown in .Fig. 1, so tha.i the liquid must flow downwardly under the bafile through that portion of the generator heated directly by the burner II.

As best shown in Fig. 2, the absorber 20 comprises an unter tubular shell 21 and an inner tubular shell 28 forming a. chamber 29 closed ab each end by suitable end p1a.tes welded or otherwise secured to the ends of the tubes 21 and 28. A partition 29 secured between and extending longitudinally of the tubes 21 und. 28 in the lower part of chamber' 29 forms with the tube 28 a partition or baflie extending upwardly within und dividing the chamber 29. Spacing members 33 are employed I;o suppor t tube 28 with respect to the outer tube 21 to facilitate assembly of the absorber.

The interior surface of thcouter tube 21 und also the outer surface cf the tube 28 a.re covered with a. capillary or wick-like material such as steel mesh 30. The conduit 2I ior weak solution from the generator to the absorber is connected to the latter on one side f the partition 29 und. the return conduit 23 for enriched absorptlon solution is connected to the absorber on the other side of the paitition 29. The gas conduits I8 and I9 from the evaporator are connected to the absorber so-that flow of gas is lengthwise and upwardly in chamber 29, the rich gas entering the lower part of the absorber through conduit I9 at one end and. leaving the upper part of the absorber from the other end through conduii;- I8.- 4 Weak absorption liquid entering the absorb'ei through conduit 2I is carried upwzirdly along the surfaces of the shells 21 and 28 by capillarity cf- The wick s 30 comprise capillary syphons which function to circulate absorption liquid thro'ugh the absorber against the action of gravit.v sind maintain the solution in bodies of extensive surface in contact with the gas, thereby aiding absorption of the ammonia vapor. Heat of absorption is removed from the liquid in its paths of flow through the absorber by transfer to the .atmosphere through inner and outer shells 28 and 21. -Although heat radiating fins 28 have been shown on the exterior of the absotber for removal of heat cf absorption, it is obvious thai; cooling water coils may be provided either or both around the unter shell 21 and the inner shell 28.

Although not shown it is also contemplated that the conduit I9 ior cool rieb gas from the evanorator may be extended in heai. exchange relation with the inner taube 28, or even that the latter may be utilized as a portion 015 the :onduit for the cool rich gas.

Circulation of absorption solution between the generator I0 and the absorber 20 is accomplished by capillarity aided by an arrangement of liquid columns of different densities eii'ected by heating and cooling. Conduit 2l for weak absorption solution is connected to the generator I0 above the liquid level 'therein and is proved in part or throughout, as shown, with a wick 3l of suitable material such as steel mesh, previously' indicated for use in the absorber. The wick 31 extends from the opening of conduit 2l in the generator I0 downwardly to the level of liquid therein on the side of the baiile 25 opposite the connection of conduit 23 for enriched absorption liquid. With this arrangement, weak absorption solution fiows by capillarity froin the liquid level in the generator upwardly in'to conduit 2l and thence into the absorber 20. As shown, conduit 2l is arranged with a firsi; downward l0op having its descending leg in heatexchange relation with the cool enriched solution in heat exchanger 24 and a second downward loop into the absorber in heat exchange relation at 32 with conduit I9 in which fiows the cool rich gas from the evaporator. The hot weak solution fiowing in conduit 2I by capillarity is cooled in the descending portions of said loops whereby the density of the liquid in these portions is increased and the fiow oi weak solution aided by gravity.

It will be obvious to. those skilled in the art that various other changes may be made in the construction and arrangement without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawing and described in the specification but only as indicated in the iollowing claims.

I claim:

1. A reirigeration system oi' the absorption type including a generator, an absorber, a capillary syphon for transferring absorption soltion from said generator to said absorber, and a conduit for enriched absorption solution from said absorber to said generator extending in heat exchange relation with a descending portion 01 said syphon.

2. A refrigeration system of the absorption type including a generator, an absorber, an evai oraigor, a capillary syphon for transferring liquid from said generator to said absorber, and a conduit for gas from said evaporator to said absorber extending in heat exchange relation with a. descending portion of said syphon.

3. A refrigeration system of the absorption type including a generator, an absorber, an evaporator, a capillary syphon for liquid from said generator to said absorber having a plurality of rising and descending portions, a conduit f0l' returning liquid from said absorber to said generator extending in thermal exchange relation with one of said descending portions, and a conduit ior gas from said evaporator to said absorber extending in thermal exchange relation with another of said descending portions.

4. A refrigeration system of the absorption type comprising a genera'tor, an absorber interconnected with said generator for the circulation cf absorption solution therebetvieen, an evap orator interconneciaed with said absorber for the circulation of inert gas therebetween, a condenser connected to receive vapor from said generator and delivcr condensate to said evaporator, and a capillary syphon for causing circulation 015 soluculation of a cooling fluid, a capillary syphon for caus ing circulation of absorption solution between said gcneraizor and absorber, and means for cooling the descending portion of said syphon.

6. In an absorption type refrigerating system including an absorption solution circuit having .a heated poition and a cooled portion, a capillary syphon f'orcausing 'circulation 015 solution through said circuit situated to lifi: liquid in said circuit.

7. In an absorption type refrigerating system including an abs0rption solution circuit having a heated portion and a cooled portion, a wick for causing circulation of solution through said circuit situated to litt liquid in said circuit. l

8. In a refrigerating system-of the absorption type, means formin'g a circuit for absorption solution, means for causing circulation of solution in said circuit comprising a capillary syphon, and means for 'maintaining the descending portion of said syphon als a lower temperature than the rising portion thereof.

9. In a refrigerating system of the absorptio type, means forming a cirouit for absorption solution, means for heating one portioh of said circuit, means ior cooling another portion of said circuit, and a capillary syphon in said circuit for causing liquid circulation therethrough, said circuit being arranged such that the descending portion of said syphon is maintained at a lower temperature than the rising portion thereof.

10. Absorption refrigerating apparatus including a generator, an absorber, a condenser, an evaporator, means to con duct vaporous reirigerant from the generator to the condenser, means to conduct liquid refrigerant from the condenser to the evaporator, means to circulate an auxiliary gas between the evaporator and the absorber, and means within said apparatus for circulating liquid between the generator and the absorber including a material capable cf attracting liquid without r'eceiving extemal energy.

11. Absorption refrigerai;ing apparatus including a gene;ator an absorber, a condenser, an evaporator, means to conduct vaporous refrigerant from the generator to the condenser, means to conduct liquid refrigerant from the condenser to the evaporator, means to circulate an auxiliary gas between the evaporator and the absorber. means within said apparatus for circulating liquid between the generator and the absorber including a naterial capable oi attracting liquid without rechring externai energy, and means to raise liquid in the absorber above the location of liquid therein due to gravity.

12. Absorption refrigerating apparatus including a generator, an absorber, a condenser, an evaporator, means to conduct vaporous refrigerant irom the generator to thecondenser'means to conduct liquid refrigerant from the condenser to the evaporator, means to -circulate an auxiliary gas between the evaporator and the absorber, capillary means for i:irculating liquid between the generator and the absorber, and can- 2,oa1,72s 3 illary means to raise liquid in the absorber into contact with the auxiliary gas above the location of liquid therein effected by said liquid circulating means.

13. Absorption refrigerating apparatus including a generator, an absorl aer, a condenser, an evaporator, means to conduct vaporous refrigerant from the generator to the condenser, means to conduct liquid refrige rant from the coudenser to the evaporator, means to circulate an auxiliary gas between the evaporator and the absorber, capillary means Ior circulating liquid between the generator and the absorber, and materi'al in the absorber capable of attracting liquid without receiving external energy to raise liquid in the absorber above the location of liquid therein due to gravity into contact with the auxiliary gas.

14. Absorption refrigerating apparatus hicluding a generator, an absorber, a condenser, an evaporator, means to conduct vaporous retrigera.nt from i;he generator to the condenser', means to couduct liquid reirigerant irom the condenser to the evaporator, xneans to clrculate an auxiliary gas between the evaporator und the absorber, a.nd liquid suction means within said apparatus for producing circulation between the generator and the absorber and f0l' raising liquid in the absorbe'r into contact with the auxiliary gas.

15. Absorption refrigerating apparatus including a generator. an absorber, a condenser, an evaporator, means to conduct vaporous refrigerant from the generator to the condenser, means to conduct liquid refrigerant trom the condenser to the evaporator, means to cir culate an auxiliary gas between the evaporator und the absorber, and capillary material within said apparatus Ior producing'"circulation between the generator and i.he absorber und for raising liquid in the absorber.

PETER KHLER. 

